1.class declaration
class Dog { //No paratheses after Dog
constructor(name,breed){
this.name=name;
this.breed=breed;
//Notice how we did not have to create const name and const breed
} //no comma here
//I repeat.. no comma after the function, just add on a new function below
bark(){
console.log(“Bark!”);
}
cuddle(){
console.log(“Love you owner”);
}
static info(){ //static method.
/*
Static method calls are made directly on the class and are not callable on instances of the class. Static methods are often used to create utility functions.
*/
console.log(“Dogs are nice”);
}
//getter
//A getter is not a method. It is a property
get description(){
return(`${this.name} is breed ${this.breed}`);
}
//This getter would be called as dogObjectVariable.description;
//setter
set nicknames(value){
this.nick = value.trim(); //removes whitespaces
/*Setter note
Accessing the property setter by its own name inside the setter creates an infinite recursive function call.
So
set nickname(valule){
this.nickname=value.trim();
would call setter nickname which calls setter nickname recursively causing a stack overflow
}
*/
}
//This setter would be set as dogObjectVariable.nicknames = "Snicky";
//getter for nicknames
get nicknames(){
return this.nick.toUpperCase();
}
}
const scooby = new Dog(“Scooby”,”Beagle”);
2.class expression
const Dog = class {
}
3.Extending classes and super
class Animal {
constructor(name) {
this.name = name;
this.thirst = 100;
this.belly = [];
}
drink() {
this.thirst -= 10;
return this.thirst;
}
eat(food) {
this.belly.push(food);
return this.belly;
}
}
class Dog extends Animal {
constructor(name, breed) {
super(name); //super initializes the class that this class is based off of
this.breed = breed;
}
bark() {
console.log('Bark bark I\'m a dog');
}
}
const rhino = new Animal('Rhiney');
const snickers = new Dog('Snickers', 'King Charles');
4.Extending arrays
We can create our own classes that are based on arrays.
class MovieCollection extends Array {
constructor(name, ...items) {
super(...items);
this.name = name;
}
add(movie) {
this.push(movie);
}
topRated(limit = 10) {
return this.sort((a, b) => (a.stars > b.stars ? -1 : 1)).slice(0, limit);
}
}
const movies = new MovieCollection('Wes\'s Fav Movies',
{ name: 'Bee Movie', stars: 10 },
{ name: 'Star Wars Trek', stars: 1 },
{ name: 'Virgin Suicides', stars: 7 },
{ name: 'King of the Road', stars: 8 }
);
movies.add({ name: 'Titanic', stars: 5 });
*Whenever you extend a class, you need to create the thing that you’re extending first before you create a class of what you want. Just call:
super();
*for…of loop only loops over iterable items
